Full keyed join failure
Full keyed join failure

A full keyed join fetch that involves nodes 2->n and where the data file
is same width as cluster and local (normal case), was very likely to either
read duff data or read of the end of the file, resulting in error:
"CFileSerialStream::get read past end of stream"
This was due to using the wrong table to map the key fpos to the local part.

Also improve error reporting and abort recovery of exception in fetch thread
handlers

Signed-off-by: Jake Smith <b20121000db38205734e8ca1c74fe9668b08552a@lexisnexis.com>

RussWhitehead/HPCC-Platform,RussWhitehead/HPCC-Platform,afishbeck/HPCC-Platform,RussWhitehead/HPCC-Platform,afishbeck/HPCC-Platform,RussWhitehead/HPCC-Platform,RussWhitehead/HPCC-Platform,RussWhitehead/HPCC-Platform,afishbeck/HPCC-Platform,afishbeck/HPCC-Platform,afishbeck/HPCC-Platform,afishbeck/HPCC-Platform,RussWhitehead/HPCC-Platform